Table 2.

Studies Assessing Clinical Presentations: studies with control group

Source	Clinical setting, Years	No. of Patients	Age, Mean (Range)	Gender (M, F)	Control group	Ref.
Plouin et al., 1981	Hypertension service, saint-Joseph hospital, Paris, France, from 1977	2585 hypertensive patients (11 of them were found to have pheochromocytoma)	33–60	1443,1142	All of the 2585 patients are considered control group as the proportion of pheochromocytoma is 0.4 %	[13]
Peter P. Stein et al. 1991	Yale university school of medicine, USA.	30 episodes (29 patients), 28 controls	37 (18–65)	13,16	Yesa	[16]
			43 (20–65)	16,12
Henry R. Black et al. 1984	11 new England hospitals, USA, 1962–1980	53 patients (60 first. 5 excluded because of finding based on predisposition genetic factor. 1 excluded because of being asymptomatic and tumor found at autopsy) 25 controls	41 (13–85)	27, 26	Yesb	[17]
			39.3 (19–85)	14,11
P.F. Plouin et al., 1988	Hypertension departments of 2 hospitals, Paris, France, 1976–1985	39 patients	---		Yes (21 patients with essential hypertension)	[20]
		21 controls
Václavík J et al. 2007	Sternberk Hospital, Sternberk, Czech Republic.	14 patients	58 (37–74)	6,8	Yesc	[23]
		214 controls	57 (16–84)	86,128
Run Yu et al. 2007	An academic hospital, Los Angeles, USA 1997–2007	40 patients	54(10–78)	16,24	Yes (patients with over-diagnosed pheochromocytoma)	[41]
		9 controls	57 (36–82)	2,7
Yu R et al. 2010	Division of Endocrinology, Cedars-Sinai Medical Center, Los Angeles, California. 2000–2008	13 patients	53 (23–86)	6,7	Yes (24 patients with highly elevated biochemical tests but pheochromocytoma was ruled out)	[47]
		24 controls	59 (28–82)	10,14

^a28 (a pheochromocytoma was considered but excluded if any 1 of several conditions were met: 1) repeatedly normal urine collections for catecholamine metabolites (VMA or MN) and urine free catecholamines (UFC) and no diagnosis of pheochromocytoma after 2 years of follow up; 2) negative imaging studies (CT, MRI or MIBG) and no diagnosis of pheochromocytoma after 2 years of follow up; 3) resolution of the clinical symptoms and/or alternate diagnosis, explaining the symptoms, established.)

^bPatients highly suspected to have pheochromocytoma in whom the diagnosis was ruled out by negative arteriograms and no evidence of disease after at least 18 months follow-up

^c213 patients screened for resistant or markedly accelerated hypertension, paroxysmal hypertension, and ‘flushes’ and, in a small proportion, for adrenal incidentaloma or genetic predisposition to pheochromocytoma. in who diagnose was not confirmed by long-term follow-up or use of imaging techniques